Given the size of the island and the population, Australia also has substantial wind power capacity per capita, and since it has built the energy storage capacity to allow it to overbuild constant-output coal power plants, the combination of opportunities to harvest from widely separated wind and solar resources and substantial capacity to firm the residual volatility with dammed pumped hydro ...

... obviously, one of the biggest hurdles would be political ... absent a 2,000km+ undersea line from Papua New Guinea to the Philippines, the only way to route the power to Thailand, Malaysia, Singapore is via Indonesia, which would threaten to put Indonesia in the position for direct electricity exports that Ukraine is in now for Russian natural gas.

Perhaps use of the electricity to produce something more fungible, like NH3, would be a better idea?

Bruce,
Australia is already exporting very large amounts of electrical energy as aluminium. It would make more sense to continue doing this if there is a "surplus" of renewable energy, rather than building transmission lines to China so that Australian minerals can be processed in China. It would make more sense for a HVDC line between China and Indian sub-continent so that mid-day solar could be used for China's afternoon peak using the 4 h time zone difference, storing some in SE Asian hydro.

Australia's priority should be to 1)expand the Bass-Link( so it doesn't become overloaded), 2)add a HVDC link to all that NG fired peak capacity and potential wind capacity in WA, and as a bonus take advantage of the 3 h summer time zone difference between WA and SE Australia to iron out peak summer demand.
and 3) start replacing coal fired electricity with solar, wind and geothermal to reduce that 27tonnes CO2e per person.

I'm not sure why you bring China into the conversation - its been about SEA.

Your three point program also needs a sustainable energy export component, or the coal lobby can always hit you over the head with the impact on the trade balance. NH3 is an area where there is active ongoing development of less capital-intensive electrical production techniques, which would make it eligible for a supply-following industrial load.

(Is the energy intensity of the aluminum processing high enough that it makes sense to overbuild peak capacity and use it as a supply-following load? Or will it, under higher international energy prices?)

The Lower Hunter has long needed (and been promised several times) a transport interchange at Glendale in northern Lake Macquarie, with a train station for Glendale Center, a road overpass over the rail line to connect Main Road Glendale to the Cardiff West Industrial estates, and a bus/rail interchange ...

... which would convert two bus cul-de-sac traffic drivers into a single through route and turn the Glendale / Town rail route into a route with peak hour traffic drivers at both ends.

And when the stimulus package was brought down, the transport infrastructure the Lower Hunter got was investment in the coal lines, to allow more coal to come from up the Hunter Valley to the coal loaders.

Because making public transport more viable and reducing dependence on driving is optional, while increasing coal exports is a national priority.